Pull-tab liner

ABSTRACT

A closure package includes a closure cap and a liner having a pull-tab. The liner is configured for use with a container having a finish or lip portion having a sealing surface at an uppermost portion thereof. The closure cap has a top wall portion and a depending skirt portion depending from the top wall portion. The top wall portion and sealing liner is adapted to coact with the container sealing surface to form a seal therebetween. The liner of the subject invention is for use with a closure package and is disposed in cap, positioned intermediate the top wall portion and the container sealing surface when the cap is positioned on the container. The liner is circular and has a central portion and a tab portion integral with the central portion, extending outwardly from a periphery thereof. The tab is folded on or above a tangent to the periphery of the liner, over the central portion into a folded position, and defines a hinge region at the juncture of the tab and above the tangential line to the liner circumference.

FIELD OF THE INVENTION

The invention relates to an inner seal for a container and moreparticularly to a pull-tab for the inner seal to permit a proper sealwhile allowing for easy removal of the inner seal to the container.

BACKGROUND OF THE INVENTION

A heat sealable inner seal is often used in sealing a container forproducts such as anti-freeze, peanut butter, mayonnaise, liquiddetergent, etc. Such an inner seal prevents leakage and is also popularfor providing an indication of whether there has been tampering with thecontents of a container.

Presently, a heat sealable inner seal generally includes a multi layercomposite structure with an upper layer of metallic foil which isattached to a lower layer of adhesive material which bonds the heat sealmaterial. The inner seal also can include an upper backing layer.Generally, the inner seals are inserted into caps and shipped to apackager of containers. The packager places the caps onto filledcontainers, with the coating of heat sealable material being in contactwith the land area of the neck of the containers. The containers thenpass through a conduction heating system which conducts heat into thefoil, under an induction heater which generates heat within the metallicfoil causing the temperature of the foil to increase. The hightemperature of the foil melts the attached heat sealable adhesive layer,causing the inner seal to bond to the container.

If the foil is heated to too low a temperature, the bonding between theheat sealable layer and container may be weak or may not occur, thuspreventing the inner seal from performing its sealing function. If themetallic foil is heated to too high a temperature, the heat sealablelayer may burn which may also prevent proper sealing. Therefore, it isdesirable to heat the foil to a temperature within a desired temperaturerange to ensure proper bonding of the inner seal to the container.

In the prior art no tabs have been used or as many as six tabs that areintegral with the central portion extend from the periphery of theliner. There may be more tabs used, as will become apparent. The tabscan serve as grasping portions, outside of the sealed periphery of thecentral portion, that facilitate removing the liner from the containerand retaining the liner within the cap.

In one known liner arrangement, a pull-tab is formed as part of theliner to facilitate removing the liner from the container. The pull-tabis a relatively small integral extension of the liner that extendsbeyond the periphery of the liner that is sealed to the container neckedge.

In order to integrate the pull-tab with a closure package, e.g., aclosure cap, a variety of configurations are in use. In one arrangement,the pull-tab is folded over the liner so as to rest within the peripheryof the liner, between the liner and the top wall of the cap when theclosure cap is placed over the liner, onto the container.

In order to assure that the tab remains flush with the liner materialduring the manufacturing process, the pull-tab is “hammered” or rolledafter it is creased and folded to create a hinge or fold. In thehammering process, a flat, hammer-like striker is driven into the tab atabout the fold or simply rolled to permanently crease the material. Whenusing relatively thin or permanently deformable material, such as foil,this arrangement is satisfactory to facilitate the tab remaining flushagainst the liner.

There are, however, a number of drawbacks to the hammered tabarrangement. First, when a relatively resilient liner material is used,the tab tends to return to its unstressed state, and unfolds, regardlessof the force used to hammer the tab into the folded position. This canbe particularly troublesome if the closure forming process is stoppedand liners have not yet been positioned inside of their respectiveclosure caps. It has been observed that the tabs tend to unfold andoften become caught or jammed on the cap threads or inner lip of thecontainer during insertion of the liner into the cap. When this occurs,the liners do not properly seat within the cap and the cap must berejected. Further, the folded tab may cover too much or too little ofthe container lip and thus result in an imperfect seal

Accordingly, there continues to be a need for a resilient liner pull-tabtherefore that correctly positions the pull-tab during induction sealingso that a positive seal is formed.

SUMMARY OF THE INVENTION

A closure package includes a closure cap and a liner having a pull-tab.The liner is configured for use with a container having a finish or lipportion having a sealing surface at an uppermost portion thereof. Theclosure cap has a top wall portion and a depending skirt portiondepending from the top wall portion. The top wall portion and sealingliner is adapted to coact with the container sealing surface to form aseal therebetween. The closure package includes a liner disposed in thecap, positioned intermediate the top wall portion and the containersealing surface when the cap is positioned on the container. The lineris circular and has a central portion and a tab portion integral withthe central portion, extending outwardly from a periphery thereof. Thetab is folded on or above a tangent to the periphery of the liner, overthe central portion into a folded position, and defines a hinge regionat the juncture of the tab and above the tangential line to the linercircumference.

The tab is scored on the hinge above region noted and folded over thecentral portion to reside within the periphery thereof. The scoring isdone to help the tab to lay flat in the closure. The same tab can beheld regardless of scoring if a tab or tabs are used on one or bothsides of the tab to hold it down.

The folded tab creates as retention area 60 that bias against linerretentive ribs or the cap threads to hold the liner in place in the capuntil sealing is performed on the bottle mouth.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an exploded perspective view of a closure package and anassociated container, the closure package including a liner having apull-tab embodying the principles of the present invention;

FIG. 2 is top plan view of a die-cut liner illustrating the linercentral portion and the pull-tab, with the pull-tab being unfolded fromthe central portion;

FIG. 3 is a top plan view of the liner of FIG. 2, illustrated with thepull-tab folded back onto the central portion;

FIG. 4 is a partial cross-sectional view of an exemplary laminatestructure of the liner material; and

FIG. 5 is a diagrammatic view of the hinge region on the tangential lineof the periphery of the liner central portion

FIG. 6 is a top plan view of a liner with a pull-tab with only oneholding tab that can be on either side of the pull-tab.

FIG. 7 is a top plan view of a liner with a pull-tab and two holdingtabs.

FIG. 8 is a top plan view of the liner of FIG. 7 showing the pull-tabfolded over.

FIG. 9 is a cross section view of a cup with a liner in place, showingthe pull-tab biasing the liner in place in the cap.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the present invention is susceptible of embodiment in variousforms, there is shown in the drawings and will hereinafter be describeda presently preferred embodiment with the understanding that the presentdisclosure is to be considered an exemplification of the invention andis not intended to limit the invention to the specific embodimentillustrated.

Referring now to the figures and particularly to FIG. 1, there is showna closure package 10 including a closure cap 12 and a liner 14 embodyingthe principles of the present invention. The package 10 is for use withan associated container 16. The exemplary container 16 has a threadedneck portion 18 having a finish 20. The finish 20 is that portion of thecontainer 16 including the upper region which engages the cap 12, e.g.,the threaded area 18 and an uppermost sealing surface 22 of thecontainer 16. The container threads 18 engage complementary threads (notshown) formed on an inner surface of the cap 12. It will be recognizedby those skilled in the art that the closure package 10 described hereincan be used with containers having a snap-like or beaded engagementconfiguration.

The cap 12 has a top wall portion 30 and a depending skirt portion 32depending from the top wall portion 30. The inner surface 34 of the topwall portion 30 is adapted to co act with the sealing surface 22 of thecontainer 16 to form a seal therebetween. When the package 10 isassembled, the liner 14 comprises a circular disc and resides betweenthe top wall portion 30 of the cap 12 and the sealing surface 22 of thecontainer 16, spanning the opening or mouth 36 of the container 16.

The liner 14 has a central portion 40 that is positioned over and inuse, sealed to the sealing surface 22 of the container 16. A tab 42 isintegral with the central portion 40, and extends from a periphery 44thereof. The tab 42 defines a grasping portion 46, that, when folded, isoutside of the sealed periphery 44 of the central portion 40, and isadapted to facilitate removing the liner 14 from the container 16. Whileshown in various shapes throughout the drawings, no particular shape isintended.

In one embodiment, as illustrated in FIG. 4, the liner 14 is formed froma laminate material M having a resilient substrate layer 50, a foil orlike gas-impermeable layer 52, and a heat activated bonding layer 54,such as a heat activated adhesive. In a current embodiment, theresilient substrate layer 50 is a closed cell foam material, but can bechip board or paper backed and/or coated and is relatively impervious tothe environs and establishes an air-tight seal between the container 16contents and the environs. The resilient material layer 50 permits thecap 12 to be closely fitted to, and tightened onto, the container 16.

During the manufacture of the closure package 10, the stock of liner 14material M is cut to form the liner tab 42. The tab 42 is folded on ahinge line that is on or above a tangential line to the liner disc andthe tab 42 is “hammered” or rolled into place. The liner 14 with thefolded and hammered tab 42 are cut to form the liner central portion 40,with the tab 42 integral with the central portion 40. Those skilled inthe art will recognize that the die that is used to cut the centralportion 40 is configured so that it does not sever the tab 42 from thecentral portion 40 of the liner 14.

Those skilled in the art will recognize that after placement of theliner 14 in the cap 12 and positioning the cap 12 on the container 16,the liner 14 must still be sealed to the sealing surface 22 of thecontainer 16. Sealing can be effected using a variety of known methods.In one method of sealing the liner 14 to the container 16, the package10 is subjected to heat, e.g., heat sealing, and the heat sensitivesealing layer 54 bonds to the sealing surface 22. Thus, the cap 12 canbe removed from the container 16 and the liner 14 remains bonded to thecontainer 16. The bonded liner 14 helps to maintain the contents of thecontainer 16 fresh, and provides tamper indication for the package 10.It is evident that the liner must be kept in place and generallycentered in the cap until the liner is sealed on the bottle mouth.

In one method of forming the package 10, a cutting from a stock of theliner material M is made to form a circular liner tab 42. As shown inFIG. 5, the tab 42 is then folded onto the liner 14 material M to form ahinge line 58 along or above a line 80 tangential to the circumference82 of the line. If the hinge line is above the tangential line, i.e.,radially beyond the circumference 82 of the liner, it should not be morethan 3 mm above.

The liner 14 material M, is cut to form the liner central portion 40.Those skilled in the art will recognize that the die that is used to cutthe central portion 40 is configured such that it does not sever the tab42 from the central portion 40. The liner 14, having the tab 42 thereon,is subsequently scored, folded, positioned and secured in the closurecap 12 to form the closure package 10. The cap 12 and liner 14 can beplaced onto the associated container 16, and the liner 14 sealed to thecontainer 16 by, for example, heat sealing. It will be recognized bythose skilled in the art that other methods of sealing the liner 14 tothe container 16 can be used to form the tamper-indicating package 10.

As stated above, a primary function of the tabs is to retain the linerin the cap prior to placement on the container and subsequent securingand sealing to the top of the container. A pull-tab is generally largerthan a regular tab so as to include a larger surface to grasp whenremoving the liner from the container. As stated, the pull-tab isgenerally larger than any regular tabs present, and is sufficientlylarge to enable a user to grasp and pull to remove the liner from thecontainer mouth. When this larger tab is folded over on top of the linerto fit inside the cap, it exerts a spring effect that tries to push theliner out of the cap during shipping and handling. To counteract thisspring effect, the subject invention folds the tab along or above thetargeted line 80 radially beyond or outside the circumference 82 of theliner disc 40 (FIG. 5). The hinge line may be formed by a practicecalled “coining” in which the liner material is lined on both sides in amanner that does not tear the material. When the tab is bent over theliner disc as shown in FIG. 3, it then secures the liner in the cap bypushing up against a thread or liner retention bead 63 biasing the lineragainst the opposite wall in the cap (see FIG. 9). If the hinge line 80is sufficiently distanced from the circumference then it may be the onlytab necessary for retaining the liner in the cap.

In this embodiment, shown in FIGS. 7 and 8, when the pull-tabs is foldedover as in FIG. 8, wings 60 and 61 are formed and serve to supplementthe retentive function of the pull-tab 42 in the cap, and form retentionareas on either side of the pull-tab.

In an alternative embodiment shown in FIG. 6, there may be other tabs 48about the liner disc, which may be equidistant about the disccircumference or randomly spaced. As many as ten additional tabs may beused, or as little as one or none. It is important when using multipletabs that at least one of the tabs is adjacent or in proximity to thepull-tab, preferably within 30° of the pull-tab.

An advantage in spacing the hinge line from the circumference of theliner is that the liner disc is better positioned over the bottle mouthso that there is no interference by the tab with the seal on the bottlemouth, i.e., the sealing process by induction heating is not interferedwith and a better seal results.

1. A liner for use with a cap and container assembly, said linercomprising: a central disc portion having a circumference; a pull-tab ona periphery of said central disc portion; said pull-tab having a hingearea parallel with a line tangential to the circumference or radiallyoutside the circumference; said pull-tab being capable of being foldedon said hinge area to lay flat over said central disc portion, wherebyin use in the cap said folded pull-tab biases said central disc portionagainst a wall of said cap.
 2. The liner of claim 1 further including atleast one tab on said periphery of said central disc portion in additionto said pull-tab.
 3. The liner of claim 2 wherein said at least one tabis in proximity to said pull-tab.
 4. The liner of claim 1 wherein saidfolded pull-tab has wings on opposing sides of said pull-tab.
 5. Theliner of claim 1 further including a plurality of tabs on said peripheryof said central disc portion.
 6. The liner of claim 5 wherein one ofsaid plurality of tabs is in proximity to said pull-tab.
 7. The liner ofclaim 2 wherein the pull-tab is larger than said at least one tab.
 8. Aliner having a pull-tab for use with a cap and container assembly, saidliner comprising: a central disc portion having a circumference; aplurality of tabs comprising first tabs and a pull-tab, said pull-tabbeing larger than the first tabs, at least one of the first tabs beingin proximity to said pull-tab, said pull-tab having a hinge areaparallel to a tangential line to said circumference and touching orradially beyond the circumference, whereby said pull-tab is folded alongsaid hinge area to be substantially flat against the central discportion and be capable of maintaining the liner within the cap wheninserted therein.
 9. The liner of claim 8 wherein the at least one offirst tabs is within 30° of the pull-tab on the circumference.
 10. Theliner of claim 8 wherein said pull-tab is larger than each of said firsttabs.
 11. A circular liner having a pull-tab for use with a cap andcontainer assembly, said liner having a pull-tab; said pull-tab having ahinge area parallel with a line tangential to a circumference of theliner or outside the tangential liner; and said pull-tab being folded onsaid hinge area for use in the cap, thereby forming retention areas onopposite sides of the pull-tab, whereby said retention areas and saidfolded pull-tab bias said liner against an opposing interior wall of thecap.
 12. The liner of claim 11 further including at least one tab onsaid periphery of said central disc portion in addition to saidpull-tab.
 13. The liner of claim 11 wherein said at least one tab is inproximity to said pull-tab.
 14. The liner of claim 11 wherein saidretention areas comprise wings.
 15. The liner of claim 11 furtherincluding a plurality of tabs on said periphery of said central discportion.
 16. The liner of claim 12 wherein said pull-tab is larger thansaid at least one tab.